ALIMENTARY CANAL OF REPTILES. 447 



with the urinary, genital, and allantoic orifices, when the latter 

 bladder persists in any degree. 



In the Batrachia 1 the allantois opens into the fore part of the 

 cloaca, or, as it seems, into that part of the rectum ; behind the 

 rectal outlet are the orifices of the two sperm-ducts or oviducts : 

 behind these are the orifices of the ureters ; the genital and 

 urinary outlets are usually prominent. The rectal orifice is less 

 distinct and constricted, and the cloaca seems more a continuation 

 of the gut than in higher Reptiles. In the male Triton the 

 rectum forms a valvular projection into the cloaca, after it has 

 received the orifices of the vasa deferentia. 



In true Ophidia there is no remnant of allantois opening into 

 the fore part of the rectum or cloaca ; in Anguis a small bladder 

 remains in that connection, 2 which expands, in limbed Lizards, to 

 larger proportions. In Coluber, as in other Serpents, the terminal 

 orifice of the rectum is well marked ; behind it is a semilunar 

 fissure, receiving the outlets of the oviducts, and behind that is 

 the bilobed prominence on which the ureters open. 3 The cloaca 

 in Lizards shows the valvular fold between the intestinal orifice 

 and those of the genital and renal conduits, together with the 

 orifice of the allantois at the fore part of the rectum. In the 

 Chelonia the allantois, fig. 302, u', opens into the fore part of the 

 cloaca, below or beyond the rectal orifice : this has a distinct 

 sphincter ; 4 the compartment of the cloaca receiving the terminal 

 orifices of the genital and urinary canal, and of the allantois, is also 

 divided by a projecting border, like a distinct orifice, from the 

 outer compartment, in which the clitoris, fig. 302, h, or penis lies : 

 the former is termed the ' urogenital,' the latter the e vestibular,' 

 part of the cloaca ; the urogenital orifice is transverse or semi-lunar. 

 In Chelydra serpentina the oviducal orifices are immediately behind 

 the rectal one : the allantoic orifice is in front of it ; behind the 

 oviducts are the terminations of the ureters, and behind these, 

 within the vestibule, arc the wide orifices of two cloacal sacculi, 5 

 each of which exceeds the allantois in size. In Emys europeea, 

 fig. 302, u, u, they equal the allantoic bladder, u'. The allantois 

 in the Crocodilia is reduced to a urinary bladder-like dilatation of 

 the fore part of the cloaca, into which the rectum opens obliquely, 

 and by a valvular protrusion ; the genital orifices are behind this, 



1 Siren, xx. vol. iv. no. 2695 ; Amphiuma, ib. no. 2397; Menopoma, ib.no. 239 ; Tor- 

 toise, ib. nos. 2401, 2699; Salamandra, ib. no. 2407; Rana, ib. nos. 2409, 2702; Pipa, 

 ib. no. 2707. 



2 xx. vol. iv. p. 57, no. 2422. 3 Ib. no. 2708. 4 Ib. vol. i. no. 751. 



5 'Anal saeculi,' xx. vol. iv. (1838) p. 147, no. 2722 b. ' Vessies auxiliares,' 

 ccxliv. (1839), p. 456. 'Vessies lombaires,' ccxxxix. torn. vi. p. 363. 



